This invention relates generally to a refrigeration system and components thereof, and in particular, to a system having different temperature zones for cooling various food and beverage articles.
People have used refrigerated devices to cool and freeze food and beverage articles for many years. Traditionally, these devices utilize a compressor functionally connected to an insulated container. The compressor and associated components and piping change the pressure of refrigerant to absorb heat from the insulated container. A fan system circulates air into and inside the insulated container. A temperature control device is typically connected to the compressor. The temperature control device cycles the compressor on and off as needed to maintain a desired temperature in the insulated container.
Cycling a compressor on and off requires a significant amount of energy and results in rather loud noises. Variable capacity compressors have been created to provide a compressor that is continuously operating. The speeds of the compressor can be varied substantially and continuously over a wide range of predefined speeds. Such compressors are disclosed in U.S. Pat. Nos. RE 33,620 to Persem and 4,765,150 to Persem.
Operation of variable capacity compressors, like all compressors, results in frost building up on the heat exchange elements. The compressors must be routinely defrosted so that the compressor may operate optimally. One method of defrosting involves running hot gas either through or near the heat exchange elements. Such defrost mechanisms are disclosed in U.S. Pat. Nos. 4,979,371 to Larson; 3,234,754 to Quick; 3,234,753 to Quick; 3,234,748 to Quick; and 3,645,109 to Quick. None of these mechanisms have been designed or utilized with variable capacity compressors. Further, all these mechanisms utilize extensive networks of tubing and control valves to accomplish defrosting.
Many refrigeration devices also have different temperature zones. For example, the common home refrigerator has a freezer section and a refrigeration section. Creating different temperatures in different sections of a refrigeration device can be accomplished in at least two methods. One method involves using a different compressor for each section. Another method involves using fans or the like to circulate cold air from a colder section to a warmer section. The operation of the fans may be controlled by a temperature control device.
For example, U.S. Pat. No. 4,505,126 to Jones et al. discloses a food product transport system, wherein motorized fans are used to circulate air from one section to another. The fans are positioned in partitions separating the different sections. U.S. Pat. No. 6,000,232 to Witten-Hannah et al. discloses a refrigeration system having a freezer section and a refrigeration section in parallel alignment. This patent further discloses a method wherein motorized fans are used to control the amount of chilled air entering each section. U.S. Pat. No. 5,081,850 to Wakatsuki et al. discloses a refrigerator that has two sections separated by a partition, wherein cool air is circulated throughout the sections and through the partition. All of these devices require the circulation of air from one section to another to create different temperatures in each section.
Accordingly, a need exists for an improved refrigeration system and components thereof that solves these and other deficiencies in the prior art. Of course, the present invention may be used in a multitude of situations where similar performance capabilities are required.